PURPOSE: To arouse attention to the malfunction of a lever for travelling.

CONSTITUTION: In a swivel joint device 4 with a shaft section 5 installed at the center of revolution of a revolving superstructure 2 for a hydraulic shovel, which has a travelling body l and the revolving superstructure 2 being arranged onto the travelling body 1 and having a driver' s cab and in which a lever for travelling driving the travelling body l is mounted into the driver's cab, and fixed onto the travelling body 1 and a body 6 engaged with the revolving superstructure 2 and rotatably fitted to the shaft section 5, a notch section 12 is formed to the outer circumferential section of the shaft section 5. A limit switch 13 detecting the presence of the notch section 12 and outputting the detection as a signal is set up to a body 6 section oppositely faced to the notch section 12 while an alarm lamp 20 informing the change of the relationship of a relative position between the travelling body 1 and the revolving superstructure 2 in response to the signal output from the limit switch 13 is provided.